The bibliometric data used to devise the citation-based metrics underpinning this ranking were collected on January 12, 2026. A core metric utilized in determining the position of each scientist within the ranking is the D-index (Discipline H-index), which is a variant of the traditional H-index. The D-index is designed exclusively to include papers and citation metrics pertinent to the specific discipline under examination—in this case, Physics—thus ensuring that the ranking fairly evaluates a researcher’s impact within their primary field of study.
Scope of Research and Qualification Criteria
The dataset analyzed for this ranking encompassed 188,172 scientist profiles identified through a variety of bibliometric data sources, spanning all scientific disciplines. From this comprehensive dataset, 5 scientists specifically identified with the field of Physics were examined for inclusion in the Singapore-focused subranking.
To qualify for the Physics-specific ranking, a scientist was required to have a minimum D-index of 70, with the majority of their tier publications demonstrably situated within the domain of Physics. In addition to quantitative bibliometric indicators, recognized awards and achievements within the discipline were taken into account during the qualification process to provide a more holistic assessment of scholarly stature.
Importantly, the D-index threshold for recognizing top researchers is dynamically set in increments of 10, calibrated according to the estimated total number of scholars in each discipline. This approach ensures that the top 1% of leading scientists are incorporated consistently, maintaining statistical rigor and relevance across fields. Furthermore, to promote disciplinary specificity and reduce cross-field bias, a proximity criterion was applied requiring the D-index to be no more than 30% lower than the researcher’s overall general H-index.
Additional Verification Practices
The Research.com team acknowledges that raw bibliometric data alone cannot be considered an absolute evaluative tool for scholarly output. Consequently, all scientist profiles included in the ranking underwent meticulous manual verification processes. These profiles were cross-correlated and validated against publications and records from a wide range of trustworthy and authoritative sources to confirm accuracy.
While the number of publications in prominent journals and conference proceedings does not directly influence a researcher’s position in the ranking, it remains a valuable secondary signal of a scientist’s contribution and impact within a specific scientific domain.
The final ranking positions are determined based on each researcher’s D-index computed from data retrieved primarily from OpenAlex and CrossRef—recognized as the leading bibliometric databases readily available to the research community.
For a more in-depth explanation of the methodology employed in constructing these rankings, we encourage readers to visit our methodology page.
Research.com’s Mission Behind the Ranking
Research.com is committed to motivating researchers, companies, and policymakers worldwide to carefully examine the trajectories of leading experts. Our mission is to provide the global scientific community with transparent, reliable, and accessible tools to identify who the leading experts are in specific fields of study. Whether within countries or among individual research institutions, our rankings aim to foster recognition and collaboration by spotlighting top scientific talent.
By underpinning this endeavor with rigorous data collection, disciplined verification, and thoughtful metrics such as the D-index, Research.com strives to uphold a credible and authoritative resource that aids academic institutions and the broader research ecosystem in their strategic decision-making and scholarly engagement.
